Geothermal Heat Pump

A Geothermal heat pump (sometimes referred to as GeoExchange, earth-coupled, ground-source, or water-source heat pump) have been in use since the late 1940s. Geothermal heat pumps (GHPs) use the constant temperature of the earth as the exchange medium instead of the outside air temperature. This allows the system to reach fairly high efficiencies (300%-600%) on the coldest of winter nights, compared to 175%-250% for air-source heat pumps on cool days.

While many parts of the country experience seasonal temperature extremes—from scorching heat in the summer to sub-zero cold in the winter—a few feet below the earth’s surface the ground remains at a relatively constant temperature. Depending on latitude, ground temperatures range from 45°F (7°C) to 75°F (21°C). Like a cave, this ground temperature is warmer than the air above it during the winter and cooler than the air in the summer. The GHP takes advantage of this by exchanging heat with the earth through a ground heat exchanger as shown in the picture.

As with any heat pump a geothermal heat pump reviews can have many pros and cons and are considered just alike with water-source heat pumps are able to heat, cool, and, if so equipped, supply the house with hot water. Some models of geothermal systems are available with two-speed compressors and variable fans for more comfort and energy savings. Relative to air-source heat pumps, they are quieter, last longer, need little maintenance, and do not depend on the temperature of the outside air. However there are some maintenance requirements but again they are minimum and are basically routine.

Put simply the geothermal heat pump uses the earth (Geo) to help in its cooling and in its heating as the above image shows. Its simple science actually. When its scorthing hot outside you know deep in the ground its cooler. When its freezing outside you know, at least 12 to 16 inches down within the earth, its warmer. That cycle is the basis for geothermal heating and cooling.

A dual-source heat pump combines an air-source heat pump with a geothermal heat pump. These appliances combine the best of both systems. Dual-source heat pumps have higher efficiency ratings than air-source units, but are not as efficient as geothermal units. The main advantage of dual-source systems is simply that a geothermal heat pump cost much less to install than a single geothermal unit, and work almost as well.

Even though the geothermal heat pump installation price or a geothermal system can be several times that of an air-source system of the same heating and cooling capacity, the additional costs are returned to you in energy savings in 5–10 years. System life is estimated at 25 years for the inside components and 50+ years for the ground loop. There are approximately 50,000 geothermal heat pumps installed in the United States each year and with the main focus on going green and saving money, look for more!